ImmutableValueGraph: Support incidentEdgeOrder=stable

RELNOTES=N/A ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=288467276
google · Jan 7, 2020 · 6c3fe55 · 6c3fe55
1 parent 845c974
commit 6c3fe55
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Showing 6 changed files with 58 additions and 2 deletions.
diff --git a/android/guava-tests/test/com/google/common/graph/ImmutableValueGraphTest.java b/android/guava-tests/test/com/google/common/graph/ImmutableValueGraphTest.java
@@ -122,4 +122,20 @@ public void immutableValueGraphBuilder_putEdgeFromEndpointPair() {
     assertThat(graph.edges()).containsExactly(EndpointPair.ordered("A", "B"));
     assertThat(graph.edgeValueOrDefault("A", "B", null)).isEqualTo(10);
   }
+
+  @Test
+  public void immutableValueGraphBuilder_incidentEdges_preservesIncidentEdgesOrder() {
+    ImmutableValueGraph<Integer, String> graph =
+        ValueGraphBuilder.directed()
+            .<Integer, String>immutable()
+            .putEdgeValue(2, 1, "2-1")
+            .putEdgeValue(2, 3, "2-3")
+            .putEdgeValue(1, 2, "1-2")
+            .build();
+
+    assertThat(graph.incidentEdges(2))
+        .containsExactly(
+            EndpointPair.ordered(2, 1), EndpointPair.ordered(2, 3), EndpointPair.ordered(1, 2))
+        .inOrder();
+  }
 }
diff --git a/android/guava/src/com/google/common/graph/ImmutableValueGraph.java b/android/guava/src/com/google/common/graph/ImmutableValueGraph.java
@@ -125,7 +125,10 @@ public static class Builder<N, V> {
     private final MutableValueGraph<N, V> mutableValueGraph;
 
     Builder(ValueGraphBuilder<N, V> graphBuilder) {
-      this.mutableValueGraph = graphBuilder.build();
+      // The incidentEdgeOrder for immutable graphs is always stable. However, we don't want to
+      // modify this builder, so we make a copy instead.
+      this.mutableValueGraph =
+          graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
     }
 
     /**

diff --git a/android/guava/src/com/google/common/graph/ValueGraphBuilder.java b/android/guava/src/com/google/common/graph/ValueGraphBuilder.java
@@ -179,6 +179,15 @@ public <N1 extends N, V1 extends V> MutableValueGraph<N1, V1> build() {
     return new ConfigurableMutableValueGraph<>(this);
   }
 
+  ValueGraphBuilder<N, V> copy() {
+    ValueGraphBuilder<N, V> newBuilder = new ValueGraphBuilder<>(directed);
+    newBuilder.allowsSelfLoops = allowsSelfLoops;
+    newBuilder.nodeOrder = nodeOrder;
+    newBuilder.expectedNodeCount = expectedNodeCount;
+    newBuilder.incidentEdgeOrder = incidentEdgeOrder;
+    return newBuilder;
+  }
+
   @SuppressWarnings("unchecked")
   private <N1 extends N, V1 extends V> ValueGraphBuilder<N1, V1> cast() {
     return (ValueGraphBuilder<N1, V1>) this;

diff --git a/guava-tests/test/com/google/common/graph/ImmutableValueGraphTest.java b/guava-tests/test/com/google/common/graph/ImmutableValueGraphTest.java
@@ -122,4 +122,20 @@ public void immutableValueGraphBuilder_putEdgeFromEndpointPair() {
     assertThat(graph.edges()).containsExactly(EndpointPair.ordered("A", "B"));
     assertThat(graph.edgeValueOrDefault("A", "B", null)).isEqualTo(10);
   }
+
+  @Test
+  public void immutableValueGraphBuilder_incidentEdges_preservesIncidentEdgesOrder() {
+    ImmutableValueGraph<Integer, String> graph =
+        ValueGraphBuilder.directed()
+            .<Integer, String>immutable()
+            .putEdgeValue(2, 1, "2-1")
+            .putEdgeValue(2, 3, "2-3")
+            .putEdgeValue(1, 2, "1-2")
+            .build();
+
+    assertThat(graph.incidentEdges(2))
+        .containsExactly(
+            EndpointPair.ordered(2, 1), EndpointPair.ordered(2, 3), EndpointPair.ordered(1, 2))
+        .inOrder();
+  }
 }
diff --git a/guava/src/com/google/common/graph/ImmutableValueGraph.java b/guava/src/com/google/common/graph/ImmutableValueGraph.java
@@ -125,7 +125,10 @@ public static class Builder<N, V> {
     private final MutableValueGraph<N, V> mutableValueGraph;
 
     Builder(ValueGraphBuilder<N, V> graphBuilder) {
-      this.mutableValueGraph = graphBuilder.build();
+      // The incidentEdgeOrder for immutable graphs is always stable. However, we don't want to
+      // modify this builder, so we make a copy instead.
+      this.mutableValueGraph =
+          graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
     }
 
     /**

diff --git a/guava/src/com/google/common/graph/ValueGraphBuilder.java b/guava/src/com/google/common/graph/ValueGraphBuilder.java
@@ -179,6 +179,15 @@ public <N1 extends N, V1 extends V> MutableValueGraph<N1, V1> build() {
     return new ConfigurableMutableValueGraph<>(this);
   }
 
+  ValueGraphBuilder<N, V> copy() {
+    ValueGraphBuilder<N, V> newBuilder = new ValueGraphBuilder<>(directed);
+    newBuilder.allowsSelfLoops = allowsSelfLoops;
+    newBuilder.nodeOrder = nodeOrder;
+    newBuilder.expectedNodeCount = expectedNodeCount;
+    newBuilder.incidentEdgeOrder = incidentEdgeOrder;
+    return newBuilder;
+  }
+
   @SuppressWarnings("unchecked")
   private <N1 extends N, V1 extends V> ValueGraphBuilder<N1, V1> cast() {
     return (ValueGraphBuilder<N1, V1>) this;